The following amino acids were identified in the plant: cystine, lysine, histidine, arginine, glycine, threonine, methionine, valine, phenylalanine, leucine, isoleucine and tryptophan (Timofeev and Khuzin, 1967).
The study of the seed protein profiles and amino acid composition of 11 Amaranthus species (including Amaranthus albus) revealed that the protein profiles were similar in all species, with similar variations in molecular weights and amounts of the main seed proteins (Juan et al., 2007).
Analysis of forage plants (including Amaranthus albus) of Spain (Bermudez, 1912) and Russia (Valiuskii et al.,1996) has been reportedInvestigation of 104 Amaranthus grain genotypes from 30 species (including Amaranthus albus, Amaranthus blitoides, Amaranthus hybridus and Amaranthus spinosus) revealed that the overall average oil content in Amaranthus grain was 5.0% ranging from 1.9 to 8.7%. Squalene concentration in oils ranged from trace to 7.3%, with an average of 4.2%.
The average contents of palmitic, oleic and linoleic acids (major fatty acids) were 22.2, 29.1, and 44.6% respectively. The average fat content in dried mature leaves of 45 Amaranthus genotypes was 1.63%, ranging from 1.08 to 2.18%.
The squalene concentration in leaf lipids, averaged 0.26%, ranging from trace to 0.77% which is much lower than that from seeds.
The major fatty acids of leaf fats were linolenic, linoleic, and palmitic. Linolenic acid ranged from 56.5 to 62.0% of total fatty acids; linoleic, from 15.5 to 24.7%; and palmitic acid, from 13.5 to 15.5%. As for the fatty acid compositions at different growth stages, fatty acid content in leaf lipid was lower in mature leaves than in young leaves.
The saturated/unsaturated ratio decreased when the leaf grew to maturity. There was a positive correlation between oil content and squalene yield, and a negative correlations were found between linoleic and either of the other two major fatty acids, palmitic and oleic (He and Cork, 2003).
Changes in lipid fatty acids associated with dormancy braking in Amaranthus albus seeds was found to occur within 4 hours after dormancy and was overcome by stimulatory red irradiation.
In irradiated seeds, the percentage of unsaturation in polar lipid increased as shown by enhanced linoleic acid content.
In seeds maintained in dormancy, the polar lipid fatty acid composition also changed, but opposite to that observed in irradiated seeds (Chadoeuf-Hannel and Taylorson, 1987).
Rutin was isolated in considerable amount from the whole plant of Amaranthus albus (tumble pigweed) (Bech and Orenchuk, 1972; Bech et al., 1977).